| → distinct 1859 1860 1861 1866 |
| new and distinct 1869 |
| new, though closely allied 1872 |
|
| → leads me to 1859 1860 |
| plainly leads to the 1861 1866 1869 1872 |
|
| → which 1859 1860 1861 |
| though only some of them, which 1866 1869 1872 |
|
| → they 1859 1860 |
| and as they would be found embedded in slightly different sub-stages of the same formation, they 1861 1866 1869 1872 |
|
| → some more closely, 1859 1860 |
| and such assuredly we do find— 1861 1866 1869 1872 |
|
| → related 1859 1860 |
| some more closely, related 1861 1866 1869 1872 |
|
|
indispensable for the preservation of all the transitional gradations between any two or more species. If such gradations were not
preserved, transitional varieties would merely appear as so many
→distinct
species. It
probable that each great period of subsidence would be interrupted by oscillations of level, and that slight climatal changes would intervene during such lengthy periods; and in these cases the inhabitants of the archipelago would
migrate, and no closely consecutive record of their modifications could be preserved in any one formation. |
|
| Very many of the marine inhabitants of the archipelago now range thousands of miles beyond its confines; and analogy
→leads me to
that it would be chiefly these far-ranging
→which
would oftenest produce new varieties; and the varieties would at first
be local or confined to one place, but if possessed of any decided advantage, or when further modified and improved, they would slowly spread and supplant their parent-forms. When such varieties returned to their ancient homes, as they would differ from their former
in a nearly uniform, though perhaps extremely slight degree,
→they
would, according to the principles followed by many palæontologists, be ranked as new and distinct species. |
|
| If
there be some degree of truth in these remarks, we have no right to expect to
in our geological formations, an infinite number of those fine transitional
on
have connected all the past and present species of the same group into one long and branching chain of life. We ought only to look for a few links,
→some more closely,
some more
→related
to each other; and these links, let them be ever so close, if found in different stages of the same formation, would, by
|
